1. Field of the Invention
This invention deals with a new constructive form of a front piece of spectacles, particularly of protective spectacles and sport goggles, said front piece being supposed to be commercialized with a series of interchangeable lenses in order to fit every kind of use of the spectacles.
Main feature of this invention is that of presenting a front piece of spectacles equipped with flexible housings for the lenses, said housing being pocket-shaped and accomplished on three sides of every rim with the exception of one arch of rim, which usually is the upper one, said housings being also provided with a locking pip, so that under proper strain a side of the eyelet of the front piece bends lightly, so that a lens can be inserted or removed after being articulated on the locking or stopping pip, one side of the rim, which usually is the upper one, being without bevelling for the housings, so that writings in relief can be accomplished on it, said writings having not only an aesthetic purpose but also a functional one, aerating the lenses.
2. Description of the Related Art
Spectacles do not only have a therapeutic or ophthalmic purpose but they also protect from the sun rays or from other causes of dazzling and from impurities or sparks during particular work activities.
Among the protective spectacles there are some for a specific use. For example there are spectacles for welders or for skiers and there are spectacles for a mixed or changeable use, still presenting a function of protection from the sun rays or from other sources that can irritate the eyes.
In this field many designes for spectacles have been realized and, to satisfy different necessities, the lenses have been made interchangeable in order to apply the most proper one for the specific situation.
The prior art is usually based on frames having a fixed front piece, on which the different kinds of lenses can be applied or removed by means of screws or clips, which fix the lenses to the front piece according to a technique that reveals itself very uneasy for the user, who usually is unexperienced and has not the proper instruments.
According to other constructive solutions of this kind of spectacles mask lenses have been accomplished, on whose edges lateral hinging elements for the side pieces and central elements for the nosepiece are applied, but also this solutions are troublesome in case of replacement of a mask with another one more proper for the new situation.
According to a further technique, front pieces of spectacles have been accomplished in flexible material, so that the lenses can be inserted or removed by means of a light strain applied on the whole structure of the front piece. Also this technique reveals itself disadvantageous, since the uniform flexibility of the front piece determines an easy disengagement of the lenses whenever an occasional strain acts on the spectacles.
The above mentioned prior art of protective spectacles presents so many disadvantages and drawbacks that the user usually wears the spectacles as they have been given to him without exploiting their supposed versatility.